Wrapping apparatus

ABSTRACT

Improved wrapping apparatus for items such as one or more toilet tissue or toweling rolls especially wherein a film of thermoplastic material is used as the wrapper. Wrinkling of the wrapper and excessive roll compression are avoided by a vacuum loaded receiver placed adjacent the articles being wrapped but on the opposite side of the wrapper so as to maintain the wrapping film in a smooth condition until wrapping is substantially completed.

Youngman et al,

I United States Patent 1151 3,705,476 Wolf 1 Dec. 12, 1972 [$41 WRAPPING APPARATUS 3,019,580 2/1952 Asbury ..s3/2so 72 Inventor: Ernest Robert Wolf A'k S.C. 1 1 en Primary Examiner-Travis S. McGehee Asslgnee: Kimberly-Quirk Corporation, Assistant Examiner-Neil-Abrams Neenah,W1s. Attorney-Daniel J. l-lanlon, William D. Herrick and 22 Filed: Jan. 12, 1971 Raymond M111" [21] App]. No.: 105,909 57] ABSTRACT Improved wrapping apparatus for items such as one or U-S. more toilet tissue or toweling tons especially wherein [S .B65b a of thermoplastic material is used as the [S8] Fleld of Search ..53/33, 210, 22 8, 234 wrappet wrinkling of the wrapper and excessive 1] compression are avoided by a vacuum loaded receiver [56] References cued placed adjacent the articles being wrapped but on the UNITED STATES PATENTS I opposite side of the wrapper so as to maintain the wrapping film in a smooth cond1t1on until wrapping is 3,505,780 4/1970 Hansen,Jr. et al..... 53/210! v substantially completed. 7 3,577,866 5/1971 Ehrenfried et al... ...53/2l0 3,380,227 4/ 1968 ..53/234 X 3 Claims, 8 Drawing Figures PATENTED DEC 12 I972 sum 2 or 3 WRAPPING APPARATUS DESCRIPTION OF THE INVENTION My invention relates generally to wrapping apparatus.

' More particularly, my invention relates to devices for wrapping relatively bulky,,compressive articles such as rolls of toilet tissue or paper toweling in thermoplastic film wrappers.

The use of thermoplastic film wrappers in the consumer products industries is becoming increasingly popular. Among the reasons for this popularity are the advantages offered by plastic films when compared to paper as the other commonly used wrapping material. For example,plastic films can be transparent; allowing the consumer to see exactly what is being purchased; they are moisture resistant, providing a high degree of protection to the contents; they are easily sealed by the use of heat, alone, or other attaching methods; and the properties of the wrapper can be modified within a wide range-for specific applications.

In the thicknesses normally used for wrapping purposes, e'.g., 0.001 to 0.0015 inch, however, plastic films are'normally quite limp. This limpness necessitates that the wrapper material be subject to complete control at all times since it will not generally support itself. In the actual wrapping step, where the film surrounds the articles, this control has proved very difficult to achieve. The result has often been wrapper slippage and a highly stretched wrapping with wrinkles which severely detract from the consumer appeal or attractiveness of the product. In spite of active pursuit by the industry for a solution to these problems, they have heretofore remained substantially unresolved. Other difficulties caused by highly stretched wrappings include square rolls and tissue folds as well as improper wrapper registration. By square rolls I mean rolls that are made flat on one or more surfaces by compression against eachother or against the wrapper itself. The folds are formed when the wrapping is so tight as to cause a roll to overlap upon itself. Both detract from the consumer appeal of the product, and the squareness may in extreme cases hinder its performance by causing the roll to unwind in a rough manner.

It is an object of my invention to provide an improved wrapper capable of handling thermoplastic films with a minimum of slippage, wrinkling, and stretching.

In accordance with the foregoing objective, it is further an object of my invention to provide wrapping apparatus that allows substantially complete control of the wrapper film in virtually all phases of the wrapping operation.

Other objects and advantages will become apparent to those skilled in this art upon reference to the detailed disclosure and to the drawings, in which,

FIG. 1 is a schematic illustration of one exemplary wrapping operation;

FIGS. 2 to 4 illustrate an embodiment of the improvement of my invention in detail; and

FIGS. 5 to 8 illustrate successive operative steps of the apparatus of my invention. I

While my invention will be described particularly with reference to thermoplastic film wrap, it will be understood by those skilled in this art that the use of paper or other form of thin wrap is not excluded although the benefits to be derived in the use of such other wrapping materials may not be quite as great as with the use of limp, thermoplastic films. The type of thermoplastic film used is not critical, and any of the known wrapping films may be utilized such as polyolefins which are coated or uncoated and vinyl films such as Saran or polyvinyl chloride.

My invention provides a modification that may be readily applied to virtually all of the known wrapping apparatus. Therefore, the description of conventional equipment is not to be considered as indicating an intent to limit my invention since those skilled in this art will recognize that equivalents may be substituted and modifications may be made to suit the particular application.

Turning now to the drawings, it will be apparent to those skilled in this art that I have described a Package Machinery Company Model U-7C wrapper which has been modified in accordance with my invention by replacing the elevator receiver plate.

FIG. 1 is apartially cut away schematic illustration of the significant operative parts of the wrapper. The apparatus is housed by frame 1 1 or other suitable support.

Supply roll 10 provides a source of thermoplastic wrapping film 12. The film passes over supportroll 14 and under slackener roll 22 connected to switch 21 (FIGS. 5-8). This switch, as is known, serves the function of activating drive roll 26 at the proper intervals. The film next is fed over support 18 for film retainer 32 which serves to prevent the film from slipping back towards supply roll 10. Pressure rolls may be used to assure a smooth sheet and a desired amount of tension in combinations with slackener roll 22. Electric eye scanning head 34 detects marks on the film to indicate proper registration. Paper brake 36 stops and holds the film as the cutter 56 severs the desired amount while guide support 38 positions the wrapping film on the side of articles 42 opposite from pusher 44 (FIGS. 5-8). The lead end of film 12 is retained by vacuum plate 74 which is timed to release as the underlap fold is made. The description to this point has dealt with equipment that is known and forms no part of my invention except that its operation may be enhanced by combination therewith.

In accordance with my invention there is included on the side of film l2 opposite from articles 42 a vacuum receiver plate 46. This plate is preferably vertically disposed and positioned in alignment with articles 42 so as to be maintained in register therewith. The vacuum is suppled by any conventional source 72 (FIGS. 5-8) such as a vacuum pump and need only be sufficient to hold the plastic film in place. I have found that a vacuum in the range of from about 18 to 22 inches of mercury is satisfactory for the thermoplastic wrapping films commonly in use today.

Vacuum plate 46 is movably attached to elevator 48 so that as the articles 42 are moved by pusher 44, film 12 is forced against vacuum plate 46 and moves it onto elevator 48 while the vacuum maintains the relative position of the articles 42 and wrap 12. By this action the free end of wrap 12 is folded under the articles 42 by the elevator bottom plates forming an underlap, and the elevator tuckers 43 make the first side folds. The elevator 48 rises by rotation about pivot 49, and the second side folds are made by a second set of similar top elevator tuckers (not shown). Then discharge pusher arm 50 attached to receiver plate 46 moves the articles 42 over bar sealing roll 82 and idler roll 84 onto front sealing plate 52 which may be a heated, release coated belt and folds the wrap under the articles in a conventional manner to form the bottom overlap. As this takes place, underlap roll 54 (FIGS. 5-8) moves down unwinding additional wrap. When scanner 34 senses the registration mark, the brake 36 is activated, and knife 56 cuts the wrap allowing the free end to drop between the elevator and the pusher 44 in position for the next wrapping operation. It will be recognized that the wrapping operation is intermittent in nature and synchronized so as to provide the desired result. Methods of timing the various steps as by cams or the like are well-known in this art, and their use will be apparent to those of ordinary skill.

Turning now to FIGS. 2 to 4, vacuum plate 46 will be described in detail. Vacuum caps 58 are mounted on receiver slide 60 by means of plate 61. The number of cups used is not critical, butI have found that providing two cups for towel rolls is advantageous in that it allows for good control of wrapper registration. Cups 58 may be of any flexible composition strong enough to maintain attachment to articles 42 through wrapper 12; however, I prefer to use cups formed of gum rubber. Fitting 62 provides for connection with vacuum hose 64 to a vacuum source (not shown). Mounts 66 may be arranged for suitable attachment to the machine as by means of screws for example.

FIGS. 5 to 8 illustrate the operation of my invention in successive stages. In FIG. 5, articles 42are adjacent pusher 44, and film 12 is between the articles and vacuum plate 46. At this point, I prefer to activate the vacuum as by means ofa microswitch or the like. Then, as shown in FIG. 6, pusher 44 moves articles 42 against the film l2 and vacuum plate 46 along receiver slide 60. From this point the vacuum maintains the film in contact with cups 58. During this operation vacuum is applied so that the film does not move with respect to vacuum cups 58 thereby preventing a change in registration or wrinkles from forming. FIG. 7 shows elevator 48 in the raised position and discharge pusher 50 about to remove the partially wrapped articles onto front sealing plate 52. At this point the vacuum is discontinued so that the film 12 may be released from vacuum plate 46 along with articles 42. I prefer to use a slight air jet blown through vacuum cups 58 to aid the release of film l2 and to keep cups 58 clean. For this purpose a reversible valve may be used to alternate vacuum and air. In these figures, successive article groups have been identified A, B, and C for clarity. In FIG. 8 the wrapped articles A are discharged for further processing along a moving belt by pusher paddle 76 and chain drive 78 while the cycle is partially completed on articles B and about to begin on articles C.

From the foregoing description it can be seen that my invention resides in providing vacuum control of the wrapper that maintains the wrapper in its relatively loose original form. As a result, when the seals are formed and the wrapped articles released, the film has not been excessively stretched, and the articles are not compressed to a degree great enough to cause them to be significantly deformed. This objectionable compression results from stresses placed on the film during wrapping. As the plastic film is wrapped around the articles, if unrestrained, it will stretch. When released and cooled, it tends to return to its original length thus exerting force on the contents. The size of the articles usually precludes the plastic film from fully shrinking so that its size is changed and complex registration problems arise if the film is printed and the printing is to appear at a specific location. As successive articles are wrapped the position of the printing tends to drift until it fails to fall within the prescribed area. At this point waste is usually created as the wrapper unwinds to reset itself through the scanning mechanism. While the waste created at a single occurrence may not be great, it is not uncommon for this to happen many times at high speed operation with a cumulative significant cost. It is, of course, usually desirable to have the wrapper contain the articles firmly so as to avoid a loose, baggy appearance. Through the use of my invention the film stretching is controlled so that a desired degree of stretch is obtained with fewer incidences of misregistration, and a better appearing product is produced.

While I am aware that it has become conventional to associate the use of vacuum with wrapping devices for such purposes as holding loose wrapper ends, suctioning away scrap, or the like, I believe thatmy invention represents its first application in the manner described to maintain a significant portion in relatively unstretched condition so as to reduce the problems resulting from a highly stretched wrapper.

Various types of vacuum devices may be employed for the purposes of my invention. These include, but are not limited to, vacuum plates, vacuum cups, vacuum pipes, etc. However, I prefer to use vacuum cups that generally conform to the shape of the article being wrapped so as to provide for even application of the vacuum.

My invention is especially useful for wrapping compressible articles such as rolls of toilet tissue or toweling where it can reduce possible deformation. However, its utility in decreasing loss from misregistration due to film stretching applies to the wrapping of other articles as well.

Accordingly, for foregoing detailed description of my invention is illustrative only and is not intended to limit its application to the specific arrangement described. On the contrary, such modifications and equivalents as may be included by interpretation of the claims are intended to form a part of my invention.

I claim:

I. In an apparatus for wrapping articles in a flexible, thermoplastic wrapping film having means for supplying said film; means for providing one or more articles to be wrapped; means for suspending said film adjacent said articles; a pusher for urging said articles against said film and drawing it about said articles; tuckers for forming end folds; an elevator for vertically displacing the partially wrapped articles; second pusher means for moving the partially wrapped articles from said elevator to a sealing plate; a cutter for severing said film supply; means for completing the wrapping and means for removing said wrapped articles;

the improvement which comprises, a vacuum receiver plate mounted on said elevator and positioned initially adjacent the wrapping film opposite from said articles; means for applying a vacuum to said vacuum receiver plate for maintaining a portion of said film in a relatively unstretched condition during wrapping; and means for moving said vacuum receiver plate relative to said elevator with said articles during wrapping.

2. Apparatus of claim 1 wherein the vacuum means 

1. In an apparatus for wrapping articles in a flexible, thermoplastic wrapping film having means for supplying said film; means for providing one or more articles to be wrapped; means for suspending said film adjacent said articles; a pusher for urging said articles against said film and drawing it about said articles; tuckers for forming end folds; an elevator for vertically displacing the partially wrapped articles; second pusher means for moving the partially wrapped articles from said elevator to a sealing plate; a cutter for severing said film supply; means for completing the wrapping and means for removing said wrapped articles; the improvement which comprises, a vacuum receiver plate mounted on said elevator and positioned initially adjacent the wrapping film opposite from said articles; means for applying a vacuum to said vacuum receiver plate for maintaining a portion of said film in a relatively unstretched condition during wrapping; and means for moving said vacuum receiver plate relative to said elevator with said articles during wrapping.
 2. Apparatus of claim 1 wherein the vacuum means comprises flexible cups shaped to conform to the articles being wrapped.
 3. Apparatus of claim 1 wherein means are provided for passing air through the vacuum receiver plate when a vacuum is not being applied so as to aid the release of said film and to remove foreign material. 